Repeatedly ignitible composition rod



Patented Mar. 13, 1951 UNITED STATES PATENT OFFICE 2,545,076 REPEATEDLY lGNlIt'lgBLE COMPOSITION Joseph Ellenbogen, London, England No Drawing. Application April 8, 1946, Serial No. 660,431. In Great Britain April 10, 1945 12 Claims. (CI. 52-29) This invention relates to repeatedly ignitable composition rods.

Various proposals have been made for the manufacture of such rods containing a combustible substance such as metaldehyde or nitrocellulose and an igniting mass which has sometimes also'been experienced in that there has been a tendency for inorganic residues to accumulate on the exposed surface of the igniting mass.

It is an obiect of the present invention to overcome these disadvantages.

Accordingly, the present in ention provides a repeatedly ignitable composition rod comprising a corecontaining an ign ting s bstance and a hydrated inorganic salt having at lea t two molecules of water of crystalli ation per mo ecule of salt and an outer layer containing a solid combustible substance such as metaldehyde and/or a n trocellulose of the pyroxylin type. 1

The igniting substance in the core may contain an easily inflammable substance such as phosphorus and/or an oxidi ing agent such as potassium chlorate. If it contains both these components the rod maybe struck on any rough surface, but if it contains only one of the components then it must be struck on a surface containing the ot er. Thus. if the core contains only an oxidising agent and a h dr ted inorganic salt then the rod s ould be struck on a surface containing phosphorus.

The rod may also cont in known combu tionretarding materials in addition to the hydrated inorganic salt. Examples of such combustionretarding materials are chalk, zinc oxide and calci m plumb te.

The hydrated inorganic salts have two main functions. Firstly. they retard combustion of the core by evaporat on of the water of hydration while the combustible ma s is burning and the inorganic re idue isles ened by the amount of water thus removed." Secondly, the salt hydrates melt at temperature below that of the flame and render the core molten or plastic and some swelling of the ma s o curs due to boiling away of the water of hydration. T is second feat re ensures that after extingui hing the flame, the core which'thenouickly sol difies .iu t protrudes from the mass of combustible material and is ready for the next ignition.

If the composition contains both an easily inflammable substance and an oxidising agent the hydrated salt has the further function that in contradistinction to the compositions of United Kingdom Specification No. 500,219, it permits an excess of oxidising agent to be used, thereby avoiding a soft phosphorus and carbonaceous residue on the end of the core after ignition.

The hydrated inorganic salt may conveniently comprise from 5% to by weight of the core.

' Examples of hydrated inorganic salts which may be u ed are: tri-sodium phosphate dodecahydrate (Na3PO4J2H2O) microcosmic salt (NaNH4HP4AH2O) and alum (A12 (S04) 3181-120) Examples of combustible substances which may be used are metaldehyde and nitrocellulose of the pvroxylin type.

The bondin of the ingredients of the composition may be effected by the use of a gum such as gum arabic but since gums are themselves combustible and may cause undesired burning of the ea ily inflammable substance and the oxidising agent it is preferred to use as a bonding agent an organo-silicon compound which polymerises to a re inous state. Any tendency towards undesired combustion is then stopped by the production of silica during the burning.

The rods of the present invention may be conveniently prepared by working up the ingredients into lastic masses and extruding the e through nozzles. The core and the outer layer may if desired be extruded through a composite nozzle in one operation.

The rod may be coated with an outer layer such as a lacnuer or an asbestos composition.

The following are examples of rods according to the invention. The parts are by weight.

1. A plastic mass for the core was prepared from an intimate mixture of parts of potassium chlorate, 6 parts of alum, 3 parts of iron oxide, 14 parts of zinc oxide, 5 parts of gum arabic in the form of a 30% aqueous solution and .7 parts of cement. jnplasticmass for the outer layer of combustible substance was prepared from an intimate mixture of parts of metaldehyde and '15 parts of nitrocellulose of the pyroxylin type in the form of a 20% by weight solution in acetone. The two plastic compositions were extruded through a composite nozzle in one operation toform a rod. After evaporation of the solvents a firm rod was obtained which was then coated with lacquer to control combustion of the outer layer. The rod can be struck on a phosphorus surface.

'2. The core consisted of an intimate mixture of 60 parts of potassium chlorate, parts of potassium nitrate, 16 parts of microcosmic salt, 1 part of iron oxide, parts of zinc oxide, 4 parts of gum arabic and=4 partsof cement. Theouter layer of combustible substance consisted of an intimate mixture of 85 parts of metaldehyde and parts of nitrocellulose of the pyroxylin type. The rod was produced as described in Example 1, and can be struck on a phosphorus surface.

3. The core consisted of an intimate mixture of 60 parts of potassium chlorate, 10 parts of sodium phosphate dodecahydrate (NasPO4.12H2O), 16 parts of silica, 5 parts of gum arabic, .1 part of iron oxide and 8 parts of cement. The outer layer of combustible substance consisted of an intimate mixture of 85 parts of metaldehyde and 15 parts of nitrocellulose of the pyroxylin type. The rod was produced as described in Example 1 and can be struck .on a phosphorus surface.

4. The core consisted ofan intimate mixture of 40 parts of potassium chlorate, 3 parts of red phosphorus, parts of microcosmic salt, 1 part of iron oxide, parts of zinc oxide, 4 parts of gum arabic and .25 parts of cement. The outer layer of combustible substance consisted of an intimate mixture .of parts of metaldehyde and 15 parts of nitrocellulose of the pyroxylin type. The rod was produced as described in Example 1 and can be struckon any rough surface.

5. The core was prepared by making an intimate mixture of parts of potassium chlorate, 4 parts of phosphorus, 16 parts of zinc oxide, 15 parts of microcosmic salt, 1 part of iron oxide, 12 parts of cement and 2 parts of ethylortho-sili- ,cate, to which was then added 4 parts of 95% industrial alcohol, which caused resinification of the ethylortho-silicate. The outer layer of combustible substance consisted of an intimate mixture of 5 parts of metaldehyde and 15 parts of nitrocellulose of the pyroxylin type. The rod was produced as described in Example 1. After evaporation of the solvent 2. firm rod was obtained which was then coated with lacquer to control combustion of the outer layer. The rod can be struck on any rough surface.

I claim:

1. A repeatedly ignitible composition rod comprising a core containing a chlorate oxidizing agent together with a hydrated inorganic salt containing at least two molecules of water of crystallization per molecule of salt and an outer layer containing metaldehyde.

2. A repeatedly ignitible composition rod comprising a core containing a chlorate oxidizing agent and phosphorus together with a hydrated inorganic salt containing at least two molecules of water of crystallization per molecule of salt and an outer layer containing metaldehyde.

3. A repeatedly ignitible composition rod comprising a core containing phosphorus, a potassium chlorate oxidizing agent, together with a hydrated inorganic salt containing at least two molecules of water of crystallization per molecule of salt and an outer layer containing metaldehyde.

4. A repeatedly ignitible composition rod comprising a core containing phosphorus, potassium chlorate and a hydrated inorganic salt containing at least two molecules of Water of crystallization per molecule of salt and an outer layer con taining metaldehyde, the proportion by weight of potassium chlorate being greater than that of phosphorus.

5. A repeatedly ignitible composition rod comprising a core containing potassium chlorate and a hydrated inorganic salt containing at least two moleculesof water of crystallization .per molecule of salt bonded "by means .of an organo-silicon compound, and an outer layer containing metaldehyde.

6. A repeatedly ignitible composition rod comprising acorecontaining potassium chlorate and alum and an outer layer containing metaldehyde anda nitrocellulose of the pyroxylin type.

'7. A repeatedly ignitible composition rod comprising a core containing potassium chlorate, potassium nitrate and microcosmic salt and an outer layer containing metaldehyde and a nitrocellulose of the pyroxylin type.

.8. A repeatedly ignitible composition rod comprising a core containing potassium chlorate and sodium phosphate dodecahydrate and an outer layer containing metaldehyde and a nitrocellulose of the pyroxylin type.

9. A repeatedly ignitible composition rod comprising a, core containing potassium chlorate, red phosphorus and microcosm'ic salt and an outer layer containing metaldehyde and a nitrocellulose of the pyroxylin type.

'10. A repeatedly ignitible composition rod-comprising a core containing a chlorate oxidizing agent, together with a hydrated inorganic microcosmic salt containing at least two molecules 'of water of crystallization per molecule of salt and an outer layer containing metaldehyde.

11. A repeatedly ignitible composition'rod comprising a core containing a chlorate oxidizing agent, together with alum containing at least two molecules of water of crystallization per molecule of salt and an outer layer containing metaldehyde.

12. A repeatedly ignitible composition rod comprising a core containing a chlorate oxidizing agent, together with sodium phosphate 'dodecahydrate, and an outer layer containing metaldehyde.

JOSEPH EILENBOGEN.

REFERENCES CITED The following references are .of record in the file of this patent:

UNITED STATE$ PATENTS Number Name Date 123,905 Howse Feb. 20, 1872 1,941,621 Ringer Jan. 2, 1934 2,138,378 Johnson Nov. 29, 1938 2,258,220 Rochow Oct. 7, 1941 2,389,491 Dunlap Nov. 20, 1945 2,408,398 Johnson Oct. 1, 1946 FOREIGN PATENTS Number Country Date 3,424 Great Britain Nov. '26, 1869 10,994 Great Britain of 1901 329,796 Great Britain May 29, 1930 401,905 Great Britain Nov. 23, 1933 500,219 Great Britain Feb. *6, 1939 OTHER REFERENCES H. D. Cogan: Properties .of Ethyl Silicate," Chemical and Engineering News, September 25, 1946, page .2501. (Copy in Patent Office Library.) 

2. A REPEATEDLY INGNITIBLE COMPOSITION ROD COMPRISING A CORE CONTAINING A CHLORIDE OXIDIZING AGENT AND PHOSPHORUS TOGETHER WITH A HYDRATED INORGANIC SALT CONTAINING AT LEAST TWO MOLECULES OF WATER OF CRYSTALLIZATION PER MOLECULE OF SAID AND AN OUTER LAYER CONTAINING METALDEHYDE. 